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An arc fault detection system (open access)

An arc fault detection system

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn, opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.
Date: December 1, 1997
Creator: Jha, Kamal N.
System: The UNT Digital Library
Constant field gradient planar cavity structure (open access)

Constant field gradient planar cavity structure

A cavity structure is described having at least two opposing planar housing members spaced apart to accommodate the passage of a particle beam through the structure between the members. Each of the housing members have a plurality of serially aligned hollows defined therein, and also passages, formed in the members, which interconnect serially adjacent hollows to provide communication between the hollows. The opposing planar housing members are spaced and aligned such that the hollows in one member cooperate with corresponding hollows in the other member to form a plurality of resonant cavities aligned along the particle beam within the cavity structure. To facilitate the obtaining of a constant field gradient within the cavity structure, the passages are configured so as to be incrementally narrower in the direction of travel of the particle beam. In addition, the spacing distance between the opposing housing members is configured to be incrementally smaller in the direction of travel of the beam.
Date: December 1, 1997
Creator: Kang, Yoon W. & Kustom, R.L.
System: The UNT Digital Library
A filtered cathodic arc deposition apparatus and method (open access)

A filtered cathodic arc deposition apparatus and method

A filtered cathodic arc deposition method and apparatus are described for the production of highly dense, wear resistant coatings which are free from macro particles. The filtered cathodic arc deposition apparatus includes a cross shaped vacuum chamber which houses a cathode target having an evaporable surface comprised of the coating material, means for generating a stream of plasma, means for generating a transverse magnetic field, and a macro particle deflector. The transverse magnetic field bends the generated stream of plasma in the direction of a substrate. Macro particles are effectively filtered from the stream of plasma by traveling, unaffected by the transverse magnetic field, along the initial path of the plasma stream to a macro particle deflector. The macro particle deflector has a preformed surface which deflects macro particles away from the substrate.
Date: December 1, 1997
Creator: Krauss, Alan R.
System: The UNT Digital Library
Cross flow flotation column for coal and minerals beneficiation (open access)

Cross flow flotation column for coal and minerals beneficiation

An apparatus and process are disclosed for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophilic tailings.
Date: December 1997
Creator: Lai, Ralph W. & Patton, Robert A.
System: The UNT Digital Library
Process for removing technetium from iron and other metals (open access)

Process for removing technetium from iron and other metals

Technetium is a radioactive product of the nuclear fission process. During reprocessing of spent or partially spent fuel from nuclear reactors, the technetium can be released and contaminate other, otherwise good, metals. A specific example is equipment in gaseous diffusion uranium enrichment cascades which have been used to process fuel which was returned from reactors, so-called reactor returns. These returns contained volatile technetium compounds which contaminated the metals in the equipment. Present regulations require that technetium be removed before the metal can be re-used at non-radioactive sites. Removing the technetium from contaminated metals has two desirable results. First, the large amount of nonradioactive metal produced by the process herein described can be recycled at a much lower cost than virgin metal can be produced. Second, large amounts of radioactively contaminated metal can be reduced to relatively small amounts of radioactive slag and large amounts of essentially uncontaminated metal. A new and improved process for removing technetium from iron and other metals is described in which between 1/10 atom % and 5 atom % of manganese is added to the contaminated metal in order to replace the technetium.
Date: December 1, 1997
Creator: Leitnaker, James M. & Trowbridge, Lee D.
System: The UNT Digital Library
Solid oxide fuel cell with multi-unit construction and prismatic design (open access)

Solid oxide fuel cell with multi-unit construction and prismatic design

A single cell unit of a solid oxide fuel cell is described that is individually fabricated and sintered prior to being connected to adjacent cells to form a solid oxide fuel cell . The single cell unit is comprised of a shaped anode sheet positioned between a flat anode sheet and an anode-electrolyte-cathode (A/E/C) sheet, and a shaped cathode sheet positioned between the A/E/C sheet and a cathode-interconnect-anode (C/I/A) sheet. An alternate embodiment comprises a shaped cathode sheet positioned between an A/E/C sheet and a C/I/A sheet. The shaped sheets form channels for conducting reactant gases. Each single cell unit is individually sintered to form a finished sub-assembly. The finished sub-assemblies are connected in electrical series by interposing connective material between the end surfaces of adjacent cells, whereby individual cells may be inspected for defects and interchanged with non-defective single cell units.
Date: December 1, 1997
Creator: McPheeters, Charles C.; Dees, Dennis W. & Myles, Kevin M.
System: The UNT Digital Library
A method for the removal of elemental mercury from a gas stream (open access)

A method for the removal of elemental mercury from a gas stream

A method is provided to remove elemental mercury from a gas stream by reacting the gas stream with an oxidizing solution to convert the elemental mercury to soluble mercury compounds. Other constituents are also oxidized. The gas stream is then passed through a wet scrubber to remove the mercuric compounds and oxidized constituents.
Date: December 1, 1997
Creator: Mendelsohn, Marshall H. & Huang, Hann-Sheng
System: The UNT Digital Library
Process management using component thermal-hydraulic function classes (open access)

Process management using component thermal-hydraulic function classes

A process management expert system for a nuclear, chemical or other process is effective following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic …
Date: December 1, 1997
Creator: Morman, James A.; Wei, Thomas Y.C. & Reifman, Jaques
System: The UNT Digital Library
Method for priming and DNA sequencing (open access)

Method for priming and DNA sequencing

A method is presented for improving the priming specificity of an oligonucleotide primer that is non-unique in a nucleic acid template which includes selecting a continuous stretch of several nucleotides in the template DNA where one of the four bases does not occur in the stretch. This also includes bringing the template DNA in contract with a non-unique primer partially or fully complimentary to the sequence immediately upstream of the selected sequence stretch. This results in polymerase-mediated differential extension of the primer in the presence of a subset of deoxyribonucleotide triphosphates that does not contain the base complementary to the base absent in the selected sequence stretch. These reactions occur at a temperature sufficiently low for allowing the extension of the non-unique primer. The method causes polymerase-mediated extension reactions in the presence of all four natural deoxyribonucleotide triphosphates or modifications. At this high temperature discrimination occurs against priming sites of the non-unique primer where the differential extension has not made the primer sufficiently stable to prime. However, the primer extended at the selected stretch is sufficiently stable to prime.
Date: December 1, 1997
Creator: Mugasimangalam, R. C. & Ulanovsky, L. E.
System: The UNT Digital Library
Method for determining aerosol particle size, device for determining aerosol particle size (open access)

Method for determining aerosol particle size, device for determining aerosol particle size

A method for determining the mass median diameter D of particles contained in a fluid is provided wherein the data of the mass of a pre-exposed and then a post-exposed filter is mathematically combined with data concerning the pressure differential across the same filter before and then after exposure to a particle-laden stream. A device for measuring particle size is also provided wherein the device utilizes the above-method for mathematically combining the easily quantifiable data.
Date: December 1, 1997
Creator: Novick, Vincent J.
System: The UNT Digital Library
Near real time vapor detection and enhancement using aerosol adsorption (open access)

Near real time vapor detection and enhancement using aerosol adsorption

A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.
Date: December 1, 1997
Creator: Novick, Vincent J. & Johnson, Stanley A.
System: The UNT Digital Library
Process and material that encapsulates solid hazardous waste (open access)

Process and material that encapsulates solid hazardous waste

A method is described for encapsulating mixed waste in which a thermoplastic polymer having a melting temperature less than about 150 C and sulfur and mixed waste are mixed at an elevated temperature not greater than about 200 C and mixed for a time sufficient to intimately mix the constituents, and then cooled to a solid. The resulting solid is also disclosed.
Date: December 1, 1997
Creator: O'Brien, Michael H. & Erickson, Arnold W.
System: The UNT Digital Library
A method for synthesizing pollucite from chabazite and cesium chloride (open access)

A method for synthesizing pollucite from chabazite and cesium chloride

A method is described for immobilizing waste chlorides salts containing radionuclides and hazardous nuclear material for permanent disposal, and in particular, a method for immobilizing waste chloride salts containing cesium, in a synthetic form of pollucite. The method for synthesizing pollucite from chabazite and cesium chloride includes mixing dry, non-aqueous cesium chloride with chabazite and heating the mixture to a temperature greater than the melting temperature of the cesium chloride, or above about 700 C. The method further comprises significantly improving the rate of retention of cesium in ceramic products comprised of a salt-loaded zeolite by adding about 10% chabazite by weight to the salt-loaded zeolite prior to conversion at elevated temperatures and pressures to the ceramic composite.
Date: August 11, 1997
Creator: Pereira, Candido
System: The UNT Digital Library
High power X-ray welding of metal-matrix composites (open access)

High power X-ray welding of metal-matrix composites

A method for joining metal-matrix composites (MMCs) by using high power x-rays as a volumetric heat source is provided. The method involves directing an x-ray to the weld line between two adjacent MMCs materials to create an irradiated region or melt zone. The x-rays have a power density greater than about 10{sup 4} watts/cm{sup 2} and provide the volumetric heat required to join the MMC materials. Importantly, the reinforcing material of the metal-matrix composites remains uniformly distributed in the melt zone, and the strength of the MMCs are not diminished. In an alternate embodiment, high power x-rays are used to provide the volumetric heat required to weld metal elements, including metal elements comprised of metal alloys. In an alternate embodiment, high power x-rays are used to provide the volumetric heat required to weld metal elements, including metal elements comprised of metal alloys.
Date: December 1, 1997
Creator: Rosenberg, Richard A.; Goeppner, George A.; Noonan, John R.; Farrell, William J. & Ma, Qing
System: The UNT Digital Library
A method and apparatus for sizing and separating warp yarns (open access)

A method and apparatus for sizing and separating warp yarns

A slashing process for preparing warp yarns for weaving operations includes the steps of sizing and/or desizing the yarns in an acoustic resonance box and separating the yarns with a leasing apparatus comprised of a set of acoustically agitated lease rods. The sizing step includes immersing the yarns in a size solution contained in an acoustic resonance box. Acoustic transducers are positioned against the exterior of the box for generating an acoustic pressure field within the size solution. Ultrasonic waves that result from the acoustic pressure field continuously agitate the size solution to effect greater mixing and more uniform application and penetration of the size onto the yarns. The sized yarns are then separated by passing the warp yarns over and under lease rods. Electroacoustic transducers generate acoustic waves along the longitudinal axis of the lease rods, creating a shearing motion on the surface of the rods for splitting the yarns.
Date: December 1, 1997
Creator: Sheen, Shuh-Haw; Chien, Hual-Te; Raptis, Apostolos C. & Kupperman, David S.
System: The UNT Digital Library
Time-of-flight SIMS/MSRI reflectron mass analyzer and method (open access)

Time-of-flight SIMS/MSRI reflectron mass analyzer and method

A method and apparatus for analyzing the surface characteristics of a sample by Secondary Ion Mass Spectroscopy (SIMS) and Mass Spectroscopy of Recoiled Ions (MSFU) is provided. The method includes detecting back scattered primary ions, low energy ejected species, and high energy ejected species by ion beam surface analysis techniques comprising positioning a ToF SIMS/MSRI mass analyzer at a predetermined angle {theta}, where {theta} is the angle between the horizontal axis of the mass analyzer and the unreflected primary ion beam line, and applying a specific voltage to the back ring of the analyzer. Preferably, {theta} is less than or equal to about 120{degree} and, more preferably, equal to 74{degree}. For positive ion analysis, the extractor, lens, and tint ring of the reflection are set at negative high voltages ({minus}Hv). The back ring of the reflection is set at greater than about +700V for MSRI measurements and between the range of about +15V and about +50V for SIMS measurements. The method further comprises inverting the polarity of the potentials applied to the extractor, lens, front ring, and back ring to obtain negative ion SIMS and/or MSRI data.
Date: December 1, 1997
Creator: Smentkowski, Vincent S.; Gruen, Dieter M.; Krauss, Alan R.; Schultz, Albert J. & Holecek, John C.
System: The UNT Digital Library
Combined heat and mass transfer device for improving separation process (open access)

Combined heat and mass transfer device for improving separation process

A two-phase small channel heat exchange matrix for providing simultaneous heat transfer and mass transfer at a single, predetermined location within a separation column, whereby the thermodynamic efficiency of the separation process is significantly improved. The small channel heat exchange matrix is comprised of a series of channels having a hydraulic diameter no greater than 5.0 mm. The channels are connected to an inlet header for supplying a two-phase coolant to the channels and an outlet header for receiving the coolant horn the channels. In operation, the matrix provides the liquid-vapor contacting surfaces within a separation column, whereby liquid descends along the exterior surfaces of the cooling channels and vapor ascends between adjacent channels within the matrix. Preferably, a perforated and concave sheet connects each channel to an adjacent channel, such that liquid further descends along the concave surfaces of the sheets and the vapor further ascends through the perforations in the sheets. The size and configuration of the small channel heat exchange matrix allows the heat and mass transfer device to be positioned within the separation column, thereby allowing precise control of the local operating conditions within the column and increasing the energy efficiency of the process.
Date: December 1, 1997
Creator: Tran, Thanh Nhon
System: The UNT Digital Library
Decontamination of matrices containing actinide oxides (open access)

Decontamination of matrices containing actinide oxides

There is provided a method for removing actinides and actinide oxides, particularly fired actinides, from soil and other contaminated matrices, comprising: (a) contacting a contaminated material with a solution of at least one inhibited fluoride and an acid to form a mixture; (b) heating the mixture of contaminated material and solution to a temperature in the range from about 30 C to about 90 C while stirring; (c) separating the solution from any undissolved matrix material in the mixture; (d) washing the undissolved matrix material to remove any residual materials; and (e) drying and returning the treated matrix material to the environment.
Date: December 1, 1997
Creator: Villarreal, Robert
System: The UNT Digital Library
Low-cost exterior insulation process and structure (open access)

Low-cost exterior insulation process and structure

The invention relates to a low-cost process for insulating walls comprising: (a) stacking bags filled with insulating material next to the exterior surface of a wall until the wall is covered, the stack of bags thus formed having fasteners to attach to a wire mesh (e.g., straps looped between the bags and fastened to the wall); (b) stretching a wire mesh (e.g., chicken wire or stucco netting) over the stack of bags, covering the side of the bags which is not adjacent to the wall; (c) fastening the wire mesh to stationary objects; (d) attaching the wire mesh to said fasteners on said stack of bags; and (e) applying a cemetitious material (e.g., stucco) to the wire mesh and allowing it to harden. Stacking the bags against the wall is preferably preceded by laying a base on the ground at the foot of the wall using a material such as cement or crushed stone wrapped in a non-woven fabric (e.g., geosynthetic felt). It is also preferred to erect stationary corner posts at the ends of the wall to be insulated, the top ends of the posts being tied to each other and/or tied or otherwise anchored to the wall. The …
Date: December 1997
Creator: Vohra, Arun
System: The UNT Digital Library